Method and apparatus for manufacturing elastic leg disposable diapers

Abstract

A method and apparatus for elasticizing the leg areas of disposable diapers is disclosed. A continuously moving elastic ribbon is attached to a continuously moving web at spaced apart locations along the length of the web corresponding to the leg areas of a finished diaper. The web is moved over an arcuate surface and the portion of the ribbon that is not attached to the web is drawn through a gap in the surface so that the unattached ribbon portion separates from the web and travels a shorter path than the web. While the web and unattached ribbon portion are separated, the unattached ribbon portion is cut so that only the ribbon portion attached to the web will have an elasticization effect on the finished diapers.

What is claimed is: 
     
       1. In an apparatus for manufacturing elastic leg disposable diapers including means for continuously moving a web of material in the direction of its length and means for attaching portions of a continuously moving elastic ribbon to the web at predetermined spaced apart locations along the length of the web, said predetermined locations corresponding to the leg areas of the finished diapers, the combination comprising: means acting in the web for separating the path of movement of the web and the elastic ribbon between said attached locations; and   means for removing the unattached portions of the elastic ribbon between said attached locations while the unattached portions are separated from the web whereby the elastic ribbon will have an elasticization affect on the web only along said attached locations corresponding to the leg areas of the finished diapers.   
     
     
       2. The combination according to claim 1 wherein said separating means comprises means for supporting only the web. 
     
     
       3. The combination according to claim 1 wherein said separating means comprises means supporting the web along a first path, said supporting means having a gap therein through which the unattached portions of the elastic ribbon move away from the web along a second path, said first path along the supporting means being longer than the second path whereby the unattached portions of the elastic ribbon are separated from the web. 
     
     
       4. The combination according to claim 3 wherein the elastic ribbon is in a stretched condition as it moves through said apparatus whereby the unattached portions of the ribbon will readily move through said gap to thereby attain a relatively relaxed condition. 
     
     
       5. The combination according to claim 3 wherein the support means comprises an arcuate surface and the gap comprises a gap through the arcuate surface. 
     
     
       6. The combination according to claim 3 wherein the support means comprises a plurality of rollers and the gap comprises a space between facing ends of the rollers. 
     
     
       7. The combination according to claims 1, 3 or 4 wherein said removing means includes means for holding the unattached portions of the moving elastic ribbon part from the web and means for cutting both ends of the unattached ribbon portions. 
     
     
       8. The combination according to claim 7 wherein said holding means comprises vacuum means. 
     
     
       9. The combination according to claim 8 wherein the vacuum means comprises a vacuum drum including a rotating cylindrical drum wall and a vacuumized stationary compartment within said drum having an opening facing the interior said of said drum wall, said opening having a length equal to the linear length of travel of the drum wall along which it is desired to hold the elastic ribbon, said drum wall having at least one opening rotating with the drum wall opposite the vacuumized compartment opening and in close proximity to the unattached portion of the elastic ribbon whereby said unattached ribbon portion is exposed to the vacuum and held against the drum wall by the vacuum to thereby tension the unattached ribbon portion during cutting and carry the cut unattached ribbon piece away after cutting as the drum wall rotates. 
     
     
       10. In a method for manufacturing elastic leg disposable diapers including continuously moving a web of material and a ribbon of elastic material into engagement with each other and attaching portions of the elastic ribbon to the web along spaced apart locations on the length of the web corresponding to the leg areas of the finished diapers, the steps comprising: during the travel of the web and elastic ribbon together, supporting the web along a path of movement that is longer than the path of movement of the portion of the elastic ribbon between the attached spaced apart locations whereby said portion of the elastic ribbon is separated from the web along the longer path of movement of the web; and   removing at least a part of the separated portion of the elastic ribbon whereby the ribbon will have an elasticization affect only along the attached locations corresponding to the leg areas of the finished diapers.   
     
     
       11. The method according to claim 10 wherein, during the supporting of the web, the portion of the elastic ribbon between the attached spaced apart locations is drawn along a path of movement that is shorter than said path of movement of the web. 
     
     
       12. The method according to claim 10 wherein elongating tension is applied to the elastic ribbon such that the portion of the elastic ribbon between the spaced apart locations readily contracts to a separated shorter path of movement than that of the web during supporting of the web along its relatively longer path of movement. 
     
     
       13. The method according to claim 12 wherein the step of removing the separated portion of the elastic ribbon includes cutting the separated portion of the elastic ribbon subsequent to applying the elongating tension to the separated portion of the elastic ribbon to thereby increase the speed of cutting of the ribbon. 
     
     
       14. The method according to claim 10 or 13 wherein said removing step includes cutting both ends of the separated portion of the elastic ribbon. 
     
     
       15. The method according to claim 14 where said removing step includes applying a vacuum to the separated portion of the elastic ribbon to carry it away subsequent to said cutting. 
     
     
       16. The method according to claim 14 wherein said removing step includes increasing the tension on the separated portion of the elastic ribbon by holding the ribbon with a vacuum and moving the area of application of the vacuum and thereby the separated portion of the ribbon in a direction away from the point of attachment of the separated portion of the ribbon with the portion of the ribbon attached to the web.